Our continued research efforts will concentrate on metabolic studies and chemotherapy of human tumors maintained in the athymic mice and in culture and immunology of the athymic mice. Investigations to determine whether the athymic mouse can serve as a model for chemotherapeutic agents for human cancers will be continued. Detailed investigations on the use of antibodies as a potential cytotoxic agent will be continued. The pareparation of conjugates using monoclonal antibodies and cytotoxic agents will be carried out. Their characteristics, chemically and biologically, will be investigated. Chemical properties of human tumors grown in the athymic mouse will be studied. The relation of growth of human tumors in the athymic mouse as related to metabolic parameters will also be investigated. The biochemical changes produced by certain factors in the growth medium of human tumor cells will be delineated. We have recently found a virulent form of mouse lymphoma in athymic mice. We shall carry out studies to determine the factors that induce this lymphoma. The biochemical parameters of this induction, as well as the chemical changes that take place in the lymphoma itself, will be studied. These lymphomas will be characterized both morphogically and biochemically.